[SPARK-13019][DOCS] fix for scala-2.10 build: Replace example code in mllib-statistics.md using include_example

## What changes were proposed in this pull request?

This PR for ticket SPARK-13019 is based on previous PR(https://github.com/apache/spark/pull/11108).
Since PR(https://github.com/apache/spark/pull/11108) is breaking scala-2.10 build, more work is needed to fix build errors.

What I did new in this PR is adding keyword argument for 'fractions':
`    val approxSample = data.sampleByKey(withReplacement = false, fractions = fractions)`
`    val exactSample = data.sampleByKeyExact(withReplacement = false, fractions = fractions)`

I reopened ticket on JIRA but sorry I don't know how to reopen a GitHub pull request, so I just submitting a new pull request.
## How was this patch tested?

Manual build testing on local machine, build based on scala-2.10.

Author: Xin Ren <iamshrek@126.com>

Closes #11901 from keypointt/SPARK-13019.
This commit is contained in:
Xin Ren 2016-03-24 09:34:54 +00:00 committed by Sean Owen
parent 048a7594e2
commit dd9ca7b960
19 changed files with 1076 additions and 382 deletions

View file

@ -10,24 +10,24 @@ displayTitle: Basic Statistics - spark.mllib
`\[
\newcommand{\R}{\mathbb{R}}
\newcommand{\E}{\mathbb{E}}
\newcommand{\E}{\mathbb{E}}
\newcommand{\x}{\mathbf{x}}
\newcommand{\y}{\mathbf{y}}
\newcommand{\wv}{\mathbf{w}}
\newcommand{\av}{\mathbf{\alpha}}
\newcommand{\bv}{\mathbf{b}}
\newcommand{\N}{\mathbb{N}}
\newcommand{\id}{\mathbf{I}}
\newcommand{\ind}{\mathbf{1}}
\newcommand{\0}{\mathbf{0}}
\newcommand{\unit}{\mathbf{e}}
\newcommand{\one}{\mathbf{1}}
\newcommand{\id}{\mathbf{I}}
\newcommand{\ind}{\mathbf{1}}
\newcommand{\0}{\mathbf{0}}
\newcommand{\unit}{\mathbf{e}}
\newcommand{\one}{\mathbf{1}}
\newcommand{\zero}{\mathbf{0}}
\]`
## Summary statistics
## Summary statistics
We provide column summary statistics for `RDD[Vector]` through the function `colStats`
We provide column summary statistics for `RDD[Vector]` through the function `colStats`
available in `Statistics`.
<div class="codetabs">
@ -40,19 +40,7 @@ total count.
Refer to the [`MultivariateStatisticalSummary` Scala docs](api/scala/index.html#org.apache.spark.mllib.stat.MultivariateStatisticalSummary) for details on the API.
{% highlight scala %}
import org.apache.spark.mllib.linalg.Vector
import org.apache.spark.mllib.stat.{MultivariateStatisticalSummary, Statistics}
val observations: RDD[Vector] = ... // an RDD of Vectors
// Compute column summary statistics.
val summary: MultivariateStatisticalSummary = Statistics.colStats(observations)
println(summary.mean) // a dense vector containing the mean value for each column
println(summary.variance) // column-wise variance
println(summary.numNonzeros) // number of nonzeros in each column
{% endhighlight %}
{% include_example scala/org/apache/spark/examples/mllib/SummaryStatisticsExample.scala %}
</div>
<div data-lang="java" markdown="1">
@ -64,24 +52,7 @@ total count.
Refer to the [`MultivariateStatisticalSummary` Java docs](api/java/org/apache/spark/mllib/stat/MultivariateStatisticalSummary.html) for details on the API.
{% highlight java %}
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.mllib.linalg.Vector;
import org.apache.spark.mllib.stat.MultivariateStatisticalSummary;
import org.apache.spark.mllib.stat.Statistics;
JavaSparkContext jsc = ...
JavaRDD<Vector> mat = ... // an RDD of Vectors
// Compute column summary statistics.
MultivariateStatisticalSummary summary = Statistics.colStats(mat.rdd());
System.out.println(summary.mean()); // a dense vector containing the mean value for each column
System.out.println(summary.variance()); // column-wise variance
System.out.println(summary.numNonzeros()); // number of nonzeros in each column
{% endhighlight %}
{% include_example java/org/apache/spark/examples/mllib/JavaSummaryStatisticsExample.java %}
</div>
<div data-lang="python" markdown="1">
@ -92,20 +63,7 @@ total count.
Refer to the [`MultivariateStatisticalSummary` Python docs](api/python/pyspark.mllib.html#pyspark.mllib.stat.MultivariateStatisticalSummary) for more details on the API.
{% highlight python %}
from pyspark.mllib.stat import Statistics
sc = ... # SparkContext
mat = ... # an RDD of Vectors
# Compute column summary statistics.
summary = Statistics.colStats(mat)
print(summary.mean())
print(summary.variance())
print(summary.numNonzeros())
{% endhighlight %}
{% include_example python/mllib/summary_statistics_example.py %}
</div>
</div>
@ -113,96 +71,38 @@ print(summary.numNonzeros())
## Correlations
Calculating the correlation between two series of data is a common operation in Statistics. In `spark.mllib`
we provide the flexibility to calculate pairwise correlations among many series. The supported
we provide the flexibility to calculate pairwise correlations among many series. The supported
correlation methods are currently Pearson's and Spearman's correlation.
<div class="codetabs">
<div data-lang="scala" markdown="1">
[`Statistics`](api/scala/index.html#org.apache.spark.mllib.stat.Statistics$) provides methods to
calculate correlations between series. Depending on the type of input, two `RDD[Double]`s or
[`Statistics`](api/scala/index.html#org.apache.spark.mllib.stat.Statistics$) provides methods to
calculate correlations between series. Depending on the type of input, two `RDD[Double]`s or
an `RDD[Vector]`, the output will be a `Double` or the correlation `Matrix` respectively.
Refer to the [`Statistics` Scala docs](api/scala/index.html#org.apache.spark.mllib.stat.Statistics) for details on the API.
{% highlight scala %}
import org.apache.spark.SparkContext
import org.apache.spark.mllib.linalg._
import org.apache.spark.mllib.stat.Statistics
val sc: SparkContext = ...
val seriesX: RDD[Double] = ... // a series
val seriesY: RDD[Double] = ... // must have the same number of partitions and cardinality as seriesX
// compute the correlation using Pearson's method. Enter "spearman" for Spearman's method. If a
// method is not specified, Pearson's method will be used by default.
val correlation: Double = Statistics.corr(seriesX, seriesY, "pearson")
val data: RDD[Vector] = ... // note that each Vector is a row and not a column
// calculate the correlation matrix using Pearson's method. Use "spearman" for Spearman's method.
// If a method is not specified, Pearson's method will be used by default.
val correlMatrix: Matrix = Statistics.corr(data, "pearson")
{% endhighlight %}
{% include_example scala/org/apache/spark/examples/mllib/CorrelationsExample.scala %}
</div>
<div data-lang="java" markdown="1">
[`Statistics`](api/java/org/apache/spark/mllib/stat/Statistics.html) provides methods to
calculate correlations between series. Depending on the type of input, two `JavaDoubleRDD`s or
[`Statistics`](api/java/org/apache/spark/mllib/stat/Statistics.html) provides methods to
calculate correlations between series. Depending on the type of input, two `JavaDoubleRDD`s or
a `JavaRDD<Vector>`, the output will be a `Double` or the correlation `Matrix` respectively.
Refer to the [`Statistics` Java docs](api/java/org/apache/spark/mllib/stat/Statistics.html) for details on the API.
{% highlight java %}
import org.apache.spark.api.java.JavaDoubleRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.mllib.linalg.*;
import org.apache.spark.mllib.stat.Statistics;
JavaSparkContext jsc = ...
JavaDoubleRDD seriesX = ... // a series
JavaDoubleRDD seriesY = ... // must have the same number of partitions and cardinality as seriesX
// compute the correlation using Pearson's method. Enter "spearman" for Spearman's method. If a
// method is not specified, Pearson's method will be used by default.
Double correlation = Statistics.corr(seriesX.srdd(), seriesY.srdd(), "pearson");
JavaRDD<Vector> data = ... // note that each Vector is a row and not a column
// calculate the correlation matrix using Pearson's method. Use "spearman" for Spearman's method.
// If a method is not specified, Pearson's method will be used by default.
Matrix correlMatrix = Statistics.corr(data.rdd(), "pearson");
{% endhighlight %}
{% include_example java/org/apache/spark/examples/mllib/JavaCorrelationsExample.java %}
</div>
<div data-lang="python" markdown="1">
[`Statistics`](api/python/pyspark.mllib.html#pyspark.mllib.stat.Statistics) provides methods to
calculate correlations between series. Depending on the type of input, two `RDD[Double]`s or
[`Statistics`](api/python/pyspark.mllib.html#pyspark.mllib.stat.Statistics) provides methods to
calculate correlations between series. Depending on the type of input, two `RDD[Double]`s or
an `RDD[Vector]`, the output will be a `Double` or the correlation `Matrix` respectively.
Refer to the [`Statistics` Python docs](api/python/pyspark.mllib.html#pyspark.mllib.stat.Statistics) for more details on the API.
{% highlight python %}
from pyspark.mllib.stat import Statistics
sc = ... # SparkContext
seriesX = ... # a series
seriesY = ... # must have the same number of partitions and cardinality as seriesX
# Compute the correlation using Pearson's method. Enter "spearman" for Spearman's method. If a
# method is not specified, Pearson's method will be used by default.
print(Statistics.corr(seriesX, seriesY, method="pearson"))
data = ... # an RDD of Vectors
# calculate the correlation matrix using Pearson's method. Use "spearman" for Spearman's method.
# If a method is not specified, Pearson's method will be used by default.
print(Statistics.corr(data, method="pearson"))
{% endhighlight %}
{% include_example python/mllib/correlations_example.py %}
</div>
</div>
@ -211,187 +111,76 @@ print(Statistics.corr(data, method="pearson"))
Unlike the other statistics functions, which reside in `spark.mllib`, stratified sampling methods,
`sampleByKey` and `sampleByKeyExact`, can be performed on RDD's of key-value pairs. For stratified
sampling, the keys can be thought of as a label and the value as a specific attribute. For example
the key can be man or woman, or document ids, and the respective values can be the list of ages
of the people in the population or the list of words in the documents. The `sampleByKey` method
will flip a coin to decide whether an observation will be sampled or not, therefore requires one
pass over the data, and provides an *expected* sample size. `sampleByKeyExact` requires significant
sampling, the keys can be thought of as a label and the value as a specific attribute. For example
the key can be man or woman, or document ids, and the respective values can be the list of ages
of the people in the population or the list of words in the documents. The `sampleByKey` method
will flip a coin to decide whether an observation will be sampled or not, therefore requires one
pass over the data, and provides an *expected* sample size. `sampleByKeyExact` requires significant
more resources than the per-stratum simple random sampling used in `sampleByKey`, but will provide
the exact sampling size with 99.99% confidence. `sampleByKeyExact` is currently not supported in
the exact sampling size with 99.99% confidence. `sampleByKeyExact` is currently not supported in
python.
<div class="codetabs">
<div data-lang="scala" markdown="1">
[`sampleByKeyExact()`](api/scala/index.html#org.apache.spark.rdd.PairRDDFunctions) allows users to
sample exactly $\lceil f_k \cdot n_k \rceil \, \forall k \in K$ items, where $f_k$ is the desired
sample exactly $\lceil f_k \cdot n_k \rceil \, \forall k \in K$ items, where $f_k$ is the desired
fraction for key $k$, $n_k$ is the number of key-value pairs for key $k$, and $K$ is the set of
keys. Sampling without replacement requires one additional pass over the RDD to guarantee sample
keys. Sampling without replacement requires one additional pass over the RDD to guarantee sample
size, whereas sampling with replacement requires two additional passes.
{% highlight scala %}
import org.apache.spark.SparkContext
import org.apache.spark.SparkContext._
import org.apache.spark.rdd.PairRDDFunctions
val sc: SparkContext = ...
val data = ... // an RDD[(K, V)] of any key value pairs
val fractions: Map[K, Double] = ... // specify the exact fraction desired from each key
// Get an exact sample from each stratum
val approxSample = data.sampleByKey(withReplacement = false, fractions)
val exactSample = data.sampleByKeyExact(withReplacement = false, fractions)
{% endhighlight %}
{% include_example scala/org/apache/spark/examples/mllib/StratifiedSamplingExample.scala %}
</div>
<div data-lang="java" markdown="1">
[`sampleByKeyExact()`](api/java/org/apache/spark/api/java/JavaPairRDD.html) allows users to
sample exactly $\lceil f_k \cdot n_k \rceil \, \forall k \in K$ items, where $f_k$ is the desired
sample exactly $\lceil f_k \cdot n_k \rceil \, \forall k \in K$ items, where $f_k$ is the desired
fraction for key $k$, $n_k$ is the number of key-value pairs for key $k$, and $K$ is the set of
keys. Sampling without replacement requires one additional pass over the RDD to guarantee sample
keys. Sampling without replacement requires one additional pass over the RDD to guarantee sample
size, whereas sampling with replacement requires two additional passes.
{% highlight java %}
import java.util.Map;
import org.apache.spark.api.java.JavaPairRDD;
import org.apache.spark.api.java.JavaSparkContext;
JavaSparkContext jsc = ...
JavaPairRDD<K, V> data = ... // an RDD of any key value pairs
Map<K, Object> fractions = ... // specify the exact fraction desired from each key
// Get an exact sample from each stratum
JavaPairRDD<K, V> approxSample = data.sampleByKey(false, fractions);
JavaPairRDD<K, V> exactSample = data.sampleByKeyExact(false, fractions);
{% endhighlight %}
{% include_example java/org/apache/spark/examples/mllib/JavaStratifiedSamplingExample.java %}
</div>
<div data-lang="python" markdown="1">
[`sampleByKey()`](api/python/pyspark.html#pyspark.RDD.sampleByKey) allows users to
sample approximately $\lceil f_k \cdot n_k \rceil \, \forall k \in K$ items, where $f_k$ is the
desired fraction for key $k$, $n_k$ is the number of key-value pairs for key $k$, and $K$ is the
sample approximately $\lceil f_k \cdot n_k \rceil \, \forall k \in K$ items, where $f_k$ is the
desired fraction for key $k$, $n_k$ is the number of key-value pairs for key $k$, and $K$ is the
set of keys.
*Note:* `sampleByKeyExact()` is currently not supported in Python.
{% highlight python %}
sc = ... # SparkContext
data = ... # an RDD of any key value pairs
fractions = ... # specify the exact fraction desired from each key as a dictionary
approxSample = data.sampleByKey(False, fractions);
{% endhighlight %}
{% include_example python/mllib/stratified_sampling_example.py %}
</div>
</div>
## Hypothesis testing
Hypothesis testing is a powerful tool in statistics to determine whether a result is statistically
significant, whether this result occurred by chance or not. `spark.mllib` currently supports Pearson's
Hypothesis testing is a powerful tool in statistics to determine whether a result is statistically
significant, whether this result occurred by chance or not. `spark.mllib` currently supports Pearson's
chi-squared ( $\chi^2$) tests for goodness of fit and independence. The input data types determine
whether the goodness of fit or the independence test is conducted. The goodness of fit test requires
whether the goodness of fit or the independence test is conducted. The goodness of fit test requires
an input type of `Vector`, whereas the independence test requires a `Matrix` as input.
`spark.mllib` also supports the input type `RDD[LabeledPoint]` to enable feature selection via chi-squared
`spark.mllib` also supports the input type `RDD[LabeledPoint]` to enable feature selection via chi-squared
independence tests.
<div class="codetabs">
<div data-lang="scala" markdown="1">
[`Statistics`](api/scala/index.html#org.apache.spark.mllib.stat.Statistics$) provides methods to
run Pearson's chi-squared tests. The following example demonstrates how to run and interpret
[`Statistics`](api/scala/index.html#org.apache.spark.mllib.stat.Statistics$) provides methods to
run Pearson's chi-squared tests. The following example demonstrates how to run and interpret
hypothesis tests.
{% highlight scala %}
import org.apache.spark.SparkContext
import org.apache.spark.mllib.linalg._
import org.apache.spark.mllib.regression.LabeledPoint
import org.apache.spark.mllib.stat.Statistics._
val sc: SparkContext = ...
val vec: Vector = ... // a vector composed of the frequencies of events
// compute the goodness of fit. If a second vector to test against is not supplied as a parameter,
// the test runs against a uniform distribution.
val goodnessOfFitTestResult = Statistics.chiSqTest(vec)
println(goodnessOfFitTestResult) // summary of the test including the p-value, degrees of freedom,
// test statistic, the method used, and the null hypothesis.
val mat: Matrix = ... // a contingency matrix
// conduct Pearson's independence test on the input contingency matrix
val independenceTestResult = Statistics.chiSqTest(mat)
println(independenceTestResult) // summary of the test including the p-value, degrees of freedom...
val obs: RDD[LabeledPoint] = ... // (feature, label) pairs.
// The contingency table is constructed from the raw (feature, label) pairs and used to conduct
// the independence test. Returns an array containing the ChiSquaredTestResult for every feature
// against the label.
val featureTestResults: Array[ChiSqTestResult] = Statistics.chiSqTest(obs)
var i = 1
featureTestResults.foreach { result =>
println(s"Column $i:\n$result")
i += 1
} // summary of the test
{% endhighlight %}
{% include_example scala/org/apache/spark/examples/mllib/HypothesisTestingExample.scala %}
</div>
<div data-lang="java" markdown="1">
[`Statistics`](api/java/org/apache/spark/mllib/stat/Statistics.html) provides methods to
run Pearson's chi-squared tests. The following example demonstrates how to run and interpret
[`Statistics`](api/java/org/apache/spark/mllib/stat/Statistics.html) provides methods to
run Pearson's chi-squared tests. The following example demonstrates how to run and interpret
hypothesis tests.
Refer to the [`ChiSqTestResult` Java docs](api/java/org/apache/spark/mllib/stat/test/ChiSqTestResult.html) for details on the API.
{% highlight java %}
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.mllib.linalg.*;
import org.apache.spark.mllib.regression.LabeledPoint;
import org.apache.spark.mllib.stat.Statistics;
import org.apache.spark.mllib.stat.test.ChiSqTestResult;
JavaSparkContext jsc = ...
Vector vec = ... // a vector composed of the frequencies of events
// compute the goodness of fit. If a second vector to test against is not supplied as a parameter,
// the test runs against a uniform distribution.
ChiSqTestResult goodnessOfFitTestResult = Statistics.chiSqTest(vec);
// summary of the test including the p-value, degrees of freedom, test statistic, the method used,
// and the null hypothesis.
System.out.println(goodnessOfFitTestResult);
Matrix mat = ... // a contingency matrix
// conduct Pearson's independence test on the input contingency matrix
ChiSqTestResult independenceTestResult = Statistics.chiSqTest(mat);
// summary of the test including the p-value, degrees of freedom...
System.out.println(independenceTestResult);
JavaRDD<LabeledPoint> obs = ... // an RDD of labeled points
// The contingency table is constructed from the raw (feature, label) pairs and used to conduct
// the independence test. Returns an array containing the ChiSquaredTestResult for every feature
// against the label.
ChiSqTestResult[] featureTestResults = Statistics.chiSqTest(obs.rdd());
int i = 1;
for (ChiSqTestResult result : featureTestResults) {
System.out.println("Column " + i + ":");
System.out.println(result); // summary of the test
i++;
}
{% endhighlight %}
{% include_example java/org/apache/spark/examples/mllib/JavaHypothesisTestingExample.java %}
</div>
<div data-lang="python" markdown="1">
@ -401,50 +190,18 @@ hypothesis tests.
Refer to the [`Statistics` Python docs](api/python/pyspark.mllib.html#pyspark.mllib.stat.Statistics) for more details on the API.
{% highlight python %}
from pyspark import SparkContext
from pyspark.mllib.linalg import Vectors, Matrices
from pyspark.mllib.regresssion import LabeledPoint
from pyspark.mllib.stat import Statistics
sc = SparkContext()
vec = Vectors.dense(...) # a vector composed of the frequencies of events
# compute the goodness of fit. If a second vector to test against is not supplied as a parameter,
# the test runs against a uniform distribution.
goodnessOfFitTestResult = Statistics.chiSqTest(vec)
print(goodnessOfFitTestResult) # summary of the test including the p-value, degrees of freedom,
# test statistic, the method used, and the null hypothesis.
mat = Matrices.dense(...) # a contingency matrix
# conduct Pearson's independence test on the input contingency matrix
independenceTestResult = Statistics.chiSqTest(mat)
print(independenceTestResult) # summary of the test including the p-value, degrees of freedom...
obs = sc.parallelize(...) # LabeledPoint(feature, label) .
# The contingency table is constructed from an RDD of LabeledPoint and used to conduct
# the independence test. Returns an array containing the ChiSquaredTestResult for every feature
# against the label.
featureTestResults = Statistics.chiSqTest(obs)
for i, result in enumerate(featureTestResults):
print("Column $d:" % (i + 1))
print(result)
{% endhighlight %}
{% include_example python/mllib/hypothesis_testing_example.py %}
</div>
</div>
Additionally, `spark.mllib` provides a 1-sample, 2-sided implementation of the Kolmogorov-Smirnov (KS) test
for equality of probability distributions. By providing the name of a theoretical distribution
(currently solely supported for the normal distribution) and its parameters, or a function to
(currently solely supported for the normal distribution) and its parameters, or a function to
calculate the cumulative distribution according to a given theoretical distribution, the user can
test the null hypothesis that their sample is drawn from that distribution. In the case that the
user tests against the normal distribution (`distName="norm"`), but does not provide distribution
parameters, the test initializes to the standard normal distribution and logs an appropriate
parameters, the test initializes to the standard normal distribution and logs an appropriate
message.
<div class="codetabs">
@ -455,21 +212,7 @@ and interpret the hypothesis tests.
Refer to the [`Statistics` Scala docs](api/scala/index.html#org.apache.spark.mllib.stat.Statistics) for details on the API.
{% highlight scala %}
import org.apache.spark.mllib.stat.Statistics
val data: RDD[Double] = ... // an RDD of sample data
// run a KS test for the sample versus a standard normal distribution
val testResult = Statistics.kolmogorovSmirnovTest(data, "norm", 0, 1)
println(testResult) // summary of the test including the p-value, test statistic,
// and null hypothesis
// if our p-value indicates significance, we can reject the null hypothesis
// perform a KS test using a cumulative distribution function of our making
val myCDF: Double => Double = ...
val testResult2 = Statistics.kolmogorovSmirnovTest(data, myCDF)
{% endhighlight %}
{% include_example scala/org/apache/spark/examples/mllib/HypothesisTestingKolmogorovSmirnovTestExample.scala %}
</div>
<div data-lang="java" markdown="1">
@ -479,23 +222,7 @@ and interpret the hypothesis tests.
Refer to the [`Statistics` Java docs](api/java/org/apache/spark/mllib/stat/Statistics.html) for details on the API.
{% highlight java %}
import java.util.Arrays;
import org.apache.spark.api.java.JavaDoubleRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.mllib.stat.Statistics;
import org.apache.spark.mllib.stat.test.KolmogorovSmirnovTestResult;
JavaSparkContext jsc = ...
JavaDoubleRDD data = jsc.parallelizeDoubles(Arrays.asList(0.2, 1.0, ...));
KolmogorovSmirnovTestResult testResult = Statistics.kolmogorovSmirnovTest(data, "norm", 0.0, 1.0);
// summary of the test including the p-value, test statistic,
// and null hypothesis
// if our p-value indicates significance, we can reject the null hypothesis
System.out.println(testResult);
{% endhighlight %}
{% include_example java/org/apache/spark/examples/mllib/JavaHypothesisTestingKolmogorovSmirnovTestExample.java %}
</div>
<div data-lang="python" markdown="1">
@ -505,19 +232,7 @@ and interpret the hypothesis tests.
Refer to the [`Statistics` Python docs](api/python/pyspark.mllib.html#pyspark.mllib.stat.Statistics) for more details on the API.
{% highlight python %}
from pyspark.mllib.stat import Statistics
parallelData = sc.parallelize([1.0, 2.0, ... ])
# run a KS test for the sample versus a standard normal distribution
testResult = Statistics.kolmogorovSmirnovTest(parallelData, "norm", 0, 1)
print(testResult) # summary of the test including the p-value, test statistic,
# and null hypothesis
# if our p-value indicates significance, we can reject the null hypothesis
# Note that the Scala functionality of calling Statistics.kolmogorovSmirnovTest with
# a lambda to calculate the CDF is not made available in the Python API
{% endhighlight %}
{% include_example python/mllib/hypothesis_testing_kolmogorov_smirnov_test_example.py %}
</div>
</div>
@ -651,21 +366,7 @@ to do so.
Refer to the [`KernelDensity` Scala docs](api/scala/index.html#org.apache.spark.mllib.stat.KernelDensity) for details on the API.
{% highlight scala %}
import org.apache.spark.mllib.stat.KernelDensity
import org.apache.spark.rdd.RDD
val data: RDD[Double] = ... // an RDD of sample data
// Construct the density estimator with the sample data and a standard deviation for the Gaussian
// kernels
val kd = new KernelDensity()
.setSample(data)
.setBandwidth(3.0)
// Find density estimates for the given values
val densities = kd.estimate(Array(-1.0, 2.0, 5.0))
{% endhighlight %}
{% include_example scala/org/apache/spark/examples/mllib/KernelDensityEstimationExample.scala %}
</div>
<div data-lang="java" markdown="1">
@ -675,21 +376,7 @@ to do so.
Refer to the [`KernelDensity` Java docs](api/java/org/apache/spark/mllib/stat/KernelDensity.html) for details on the API.
{% highlight java %}
import org.apache.spark.mllib.stat.KernelDensity;
import org.apache.spark.rdd.RDD;
RDD<Double> data = ... // an RDD of sample data
// Construct the density estimator with the sample data and a standard deviation for the Gaussian
// kernels
KernelDensity kd = new KernelDensity()
.setSample(data)
.setBandwidth(3.0);
// Find density estimates for the given values
double[] densities = kd.estimate(new double[] {-1.0, 2.0, 5.0});
{% endhighlight %}
{% include_example java/org/apache/spark/examples/mllib/JavaKernelDensityEstimationExample.java %}
</div>
<div data-lang="python" markdown="1">
@ -699,20 +386,7 @@ to do so.
Refer to the [`KernelDensity` Python docs](api/python/pyspark.mllib.html#pyspark.mllib.stat.KernelDensity) for more details on the API.
{% highlight python %}
from pyspark.mllib.stat import KernelDensity
data = ... # an RDD of sample data
# Construct the density estimator with the sample data and a standard deviation for the Gaussian
# kernels
kd = KernelDensity()
kd.setSample(data)
kd.setBandwidth(3.0)
# Find density estimates for the given values
densities = kd.estimate([-1.0, 2.0, 5.0])
{% endhighlight %}
{% include_example python/mllib/kernel_density_estimation_example.py %}
</div>
</div>

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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.spark.examples.mllib;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaSparkContext;
// $example on$
import java.util.Arrays;
import org.apache.spark.api.java.JavaDoubleRDD;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.mllib.linalg.Matrix;
import org.apache.spark.mllib.linalg.Vector;
import org.apache.spark.mllib.linalg.Vectors;
import org.apache.spark.mllib.stat.Statistics;
// $example off$
public class JavaCorrelationsExample {
public static void main(String[] args) {
SparkConf conf = new SparkConf().setAppName("JavaCorrelationsExample");
JavaSparkContext jsc = new JavaSparkContext(conf);
// $example on$
JavaDoubleRDD seriesX = jsc.parallelizeDoubles(
Arrays.asList(1.0, 2.0, 3.0, 3.0, 5.0)); // a series
// must have the same number of partitions and cardinality as seriesX
JavaDoubleRDD seriesY = jsc.parallelizeDoubles(
Arrays.asList(11.0, 22.0, 33.0, 33.0, 555.0));
// compute the correlation using Pearson's method. Enter "spearman" for Spearman's method.
// If a method is not specified, Pearson's method will be used by default.
Double correlation = Statistics.corr(seriesX.srdd(), seriesY.srdd(), "pearson");
System.out.println("Correlation is: " + correlation);
// note that each Vector is a row and not a column
JavaRDD<Vector> data = jsc.parallelize(
Arrays.asList(
Vectors.dense(1.0, 10.0, 100.0),
Vectors.dense(2.0, 20.0, 200.0),
Vectors.dense(5.0, 33.0, 366.0)
)
);
// calculate the correlation matrix using Pearson's method. Use "spearman" for Spearman's method.
// If a method is not specified, Pearson's method will be used by default.
Matrix correlMatrix = Statistics.corr(data.rdd(), "pearson");
System.out.println(correlMatrix.toString());
// $example off$
jsc.stop();
}
}

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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.spark.examples.mllib;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaSparkContext;
// $example on$
import java.util.Arrays;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.mllib.linalg.Matrices;
import org.apache.spark.mllib.linalg.Matrix;
import org.apache.spark.mllib.linalg.Vector;
import org.apache.spark.mllib.linalg.Vectors;
import org.apache.spark.mllib.regression.LabeledPoint;
import org.apache.spark.mllib.stat.Statistics;
import org.apache.spark.mllib.stat.test.ChiSqTestResult;
// $example off$
public class JavaHypothesisTestingExample {
public static void main(String[] args) {
SparkConf conf = new SparkConf().setAppName("JavaHypothesisTestingExample");
JavaSparkContext jsc = new JavaSparkContext(conf);
// $example on$
// a vector composed of the frequencies of events
Vector vec = Vectors.dense(0.1, 0.15, 0.2, 0.3, 0.25);
// compute the goodness of fit. If a second vector to test against is not supplied
// as a parameter, the test runs against a uniform distribution.
ChiSqTestResult goodnessOfFitTestResult = Statistics.chiSqTest(vec);
// summary of the test including the p-value, degrees of freedom, test statistic,
// the method used, and the null hypothesis.
System.out.println(goodnessOfFitTestResult + "\n");
// Create a contingency matrix ((1.0, 2.0), (3.0, 4.0), (5.0, 6.0))
Matrix mat = Matrices.dense(3, 2, new double[]{1.0, 3.0, 5.0, 2.0, 4.0, 6.0});
// conduct Pearson's independence test on the input contingency matrix
ChiSqTestResult independenceTestResult = Statistics.chiSqTest(mat);
// summary of the test including the p-value, degrees of freedom...
System.out.println(independenceTestResult + "\n");
// an RDD of labeled points
JavaRDD<LabeledPoint> obs = jsc.parallelize(
Arrays.asList(
new LabeledPoint(1.0, Vectors.dense(1.0, 0.0, 3.0)),
new LabeledPoint(1.0, Vectors.dense(1.0, 2.0, 0.0)),
new LabeledPoint(-1.0, Vectors.dense(-1.0, 0.0, -0.5))
)
);
// The contingency table is constructed from the raw (feature, label) pairs and used to conduct
// the independence test. Returns an array containing the ChiSquaredTestResult for every feature
// against the label.
ChiSqTestResult[] featureTestResults = Statistics.chiSqTest(obs.rdd());
int i = 1;
for (ChiSqTestResult result : featureTestResults) {
System.out.println("Column " + i + ":");
System.out.println(result + "\n"); // summary of the test
i++;
}
// $example off$
jsc.stop();
}
}

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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.spark.examples.mllib;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaSparkContext;
// $example on$
import java.util.Arrays;
import org.apache.spark.api.java.JavaDoubleRDD;
import org.apache.spark.mllib.stat.Statistics;
import org.apache.spark.mllib.stat.test.KolmogorovSmirnovTestResult;
// $example off$
public class JavaHypothesisTestingKolmogorovSmirnovTestExample {
public static void main(String[] args) {
SparkConf conf =
new SparkConf().setAppName("JavaHypothesisTestingKolmogorovSmirnovTestExample");
JavaSparkContext jsc = new JavaSparkContext(conf);
// $example on$
JavaDoubleRDD data = jsc.parallelizeDoubles(Arrays.asList(0.1, 0.15, 0.2, 0.3, 0.25));
KolmogorovSmirnovTestResult testResult =
Statistics.kolmogorovSmirnovTest(data, "norm", 0.0, 1.0);
// summary of the test including the p-value, test statistic, and null hypothesis
// if our p-value indicates significance, we can reject the null hypothesis
System.out.println(testResult);
// $example off$
jsc.stop();
}
}

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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.spark.examples.mllib;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaSparkContext;
// $example on$
import java.util.Arrays;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.mllib.stat.KernelDensity;
// $example off$
public class JavaKernelDensityEstimationExample {
public static void main(String[] args) {
SparkConf conf = new SparkConf().setAppName("JavaKernelDensityEstimationExample");
JavaSparkContext jsc = new JavaSparkContext(conf);
// $example on$
// an RDD of sample data
JavaRDD<Double> data = jsc.parallelize(
Arrays.asList(1.0, 1.0, 1.0, 2.0, 3.0, 4.0, 5.0, 5.0, 6.0, 7.0, 8.0, 9.0, 9.0));
// Construct the density estimator with the sample data
// and a standard deviation for the Gaussian kernels
KernelDensity kd = new KernelDensity().setSample(data).setBandwidth(3.0);
// Find density estimates for the given values
double[] densities = kd.estimate(new double[]{-1.0, 2.0, 5.0});
System.out.println(Arrays.toString(densities));
// $example off$
jsc.stop();
}
}

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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.spark.examples.mllib;
import com.google.common.collect.ImmutableMap;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaSparkContext;
// $example on$
import java.util.*;
import scala.Tuple2;
import org.apache.spark.api.java.JavaPairRDD;
import org.apache.spark.api.java.function.VoidFunction;
// $example off$
public class JavaStratifiedSamplingExample {
public static void main(String[] args) {
SparkConf conf = new SparkConf().setAppName("JavaStratifiedSamplingExample");
JavaSparkContext jsc = new JavaSparkContext(conf);
// $example on$
List<Tuple2<Integer, Character>> list = new ArrayList<Tuple2<Integer, Character>>(
Arrays.<Tuple2<Integer, Character>>asList(
new Tuple2(1, 'a'),
new Tuple2(1, 'b'),
new Tuple2(2, 'c'),
new Tuple2(2, 'd'),
new Tuple2(2, 'e'),
new Tuple2(3, 'f')
)
);
JavaPairRDD<Integer, Character> data = jsc.parallelizePairs(list);
// specify the exact fraction desired from each key Map<K, Object>
ImmutableMap<Integer, Object> fractions =
ImmutableMap.of(1, (Object)0.1, 2, (Object) 0.6, 3, (Object) 0.3);
// Get an approximate sample from each stratum
JavaPairRDD<Integer, Character> approxSample = data.sampleByKey(false, fractions);
// Get an exact sample from each stratum
JavaPairRDD<Integer, Character> exactSample = data.sampleByKeyExact(false, fractions);
// $example off$
System.out.println("approxSample size is " + approxSample.collect().size());
for (Tuple2<Integer, Character> t : approxSample.collect()) {
System.out.println(t._1() + " " + t._2());
}
System.out.println("exactSample size is " + exactSample.collect().size());
for (Tuple2<Integer, Character> t : exactSample.collect()) {
System.out.println(t._1() + " " + t._2());
}
jsc.stop();
}
}

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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.spark.examples.mllib;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaSparkContext;
// $example on$
import java.util.Arrays;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.mllib.linalg.Vector;
import org.apache.spark.mllib.linalg.Vectors;
import org.apache.spark.mllib.stat.MultivariateStatisticalSummary;
import org.apache.spark.mllib.stat.Statistics;
// $example off$
public class JavaSummaryStatisticsExample {
public static void main(String[] args) {
SparkConf conf = new SparkConf().setAppName("JavaSummaryStatisticsExample");
JavaSparkContext jsc = new JavaSparkContext(conf);
// $example on$
JavaRDD<Vector> mat = jsc.parallelize(
Arrays.asList(
Vectors.dense(1.0, 10.0, 100.0),
Vectors.dense(2.0, 20.0, 200.0),
Vectors.dense(3.0, 30.0, 300.0)
)
); // an RDD of Vectors
// Compute column summary statistics.
MultivariateStatisticalSummary summary = Statistics.colStats(mat.rdd());
System.out.println(summary.mean()); // a dense vector containing the mean value for each column
System.out.println(summary.variance()); // column-wise variance
System.out.println(summary.numNonzeros()); // number of nonzeros in each column
// $example off$
jsc.stop();
}
}

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#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
from __future__ import print_function
import numpy as np
from pyspark import SparkContext
# $example on$
from pyspark.mllib.stat import Statistics
# $example off$
if __name__ == "__main__":
sc = SparkContext(appName="CorrelationsExample") # SparkContext
# $example on$
seriesX = sc.parallelize([1.0, 2.0, 3.0, 3.0, 5.0]) # a series
# seriesY must have the same number of partitions and cardinality as seriesX
seriesY = sc.parallelize([11.0, 22.0, 33.0, 33.0, 555.0])
# Compute the correlation using Pearson's method. Enter "spearman" for Spearman's method.
# If a method is not specified, Pearson's method will be used by default.
print("Correlation is: " + str(Statistics.corr(seriesX, seriesY, method="pearson")))
data = sc.parallelize(
[np.array([1.0, 10.0, 100.0]), np.array([2.0, 20.0, 200.0]), np.array([5.0, 33.0, 366.0])]
) # an RDD of Vectors
# calculate the correlation matrix using Pearson's method. Use "spearman" for Spearman's method.
# If a method is not specified, Pearson's method will be used by default.
print(Statistics.corr(data, method="pearson"))
# $example off$
sc.stop()

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#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
from __future__ import print_function
from pyspark import SparkContext
# $example on$
from pyspark.mllib.linalg import Matrices, Vectors
from pyspark.mllib.regression import LabeledPoint
from pyspark.mllib.stat import Statistics
# $example off$
if __name__ == "__main__":
sc = SparkContext(appName="HypothesisTestingExample")
# $example on$
vec = Vectors.dense(0.1, 0.15, 0.2, 0.3, 0.25) # a vector composed of the frequencies of events
# compute the goodness of fit. If a second vector to test against
# is not supplied as a parameter, the test runs against a uniform distribution.
goodnessOfFitTestResult = Statistics.chiSqTest(vec)
# summary of the test including the p-value, degrees of freedom,
# test statistic, the method used, and the null hypothesis.
print("%s\n" % goodnessOfFitTestResult)
mat = Matrices.dense(3, 2, [1.0, 3.0, 5.0, 2.0, 4.0, 6.0]) # a contingency matrix
# conduct Pearson's independence test on the input contingency matrix
independenceTestResult = Statistics.chiSqTest(mat)
# summary of the test including the p-value, degrees of freedom,
# test statistic, the method used, and the null hypothesis.
print("%s\n" % independenceTestResult)
obs = sc.parallelize(
[LabeledPoint(1.0, [1.0, 0.0, 3.0]),
LabeledPoint(1.0, [1.0, 2.0, 0.0]),
LabeledPoint(1.0, [-1.0, 0.0, -0.5])]
) # LabeledPoint(feature, label)
# The contingency table is constructed from an RDD of LabeledPoint and used to conduct
# the independence test. Returns an array containing the ChiSquaredTestResult for every feature
# against the label.
featureTestResults = Statistics.chiSqTest(obs)
for i, result in enumerate(featureTestResults):
print("Column %d:\n%s" % (i + 1, result))
# $example off$
sc.stop()

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#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
from __future__ import print_function
from pyspark import SparkContext
# $example on$
from pyspark.mllib.stat import Statistics
# $example off$
if __name__ == "__main__":
sc = SparkContext(appName="HypothesisTestingKolmogorovSmirnovTestExample")
# $example on$
parallelData = sc.parallelize([0.1, 0.15, 0.2, 0.3, 0.25])
# run a KS test for the sample versus a standard normal distribution
testResult = Statistics.kolmogorovSmirnovTest(parallelData, "norm", 0, 1)
# summary of the test including the p-value, test statistic, and null hypothesis
# if our p-value indicates significance, we can reject the null hypothesis
# Note that the Scala functionality of calling Statistics.kolmogorovSmirnovTest with
# a lambda to calculate the CDF is not made available in the Python API
print(testResult)
# $example off$
sc.stop()

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#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
from __future__ import print_function
from pyspark import SparkContext
# $example on$
from pyspark.mllib.stat import KernelDensity
# $example off$
if __name__ == "__main__":
sc = SparkContext(appName="KernelDensityEstimationExample") # SparkContext
# $example on$
# an RDD of sample data
data = sc.parallelize([1.0, 1.0, 1.0, 2.0, 3.0, 4.0, 5.0, 5.0, 6.0, 7.0, 8.0, 9.0, 9.0])
# Construct the density estimator with the sample data and a standard deviation for the Gaussian
# kernels
kd = KernelDensity()
kd.setSample(data)
kd.setBandwidth(3.0)
# Find density estimates for the given values
densities = kd.estimate([-1.0, 2.0, 5.0])
# $example off$
print(densities)
sc.stop()

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#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
from __future__ import print_function
from pyspark import SparkContext
if __name__ == "__main__":
sc = SparkContext(appName="StratifiedSamplingExample") # SparkContext
# $example on$
# an RDD of any key value pairs
data = sc.parallelize([(1, 'a'), (1, 'b'), (2, 'c'), (2, 'd'), (2, 'e'), (3, 'f')])
# specify the exact fraction desired from each key as a dictionary
fractions = {1: 0.1, 2: 0.6, 3: 0.3}
approxSample = data.sampleByKey(False, fractions)
# $example off$
for each in approxSample.collect():
print(each)
sc.stop()

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#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
from __future__ import print_function
from pyspark import SparkContext
# $example on$
import numpy as np
from pyspark.mllib.stat import Statistics
# $example off$
if __name__ == "__main__":
sc = SparkContext(appName="SummaryStatisticsExample") # SparkContext
# $example on$
mat = sc.parallelize(
[np.array([1.0, 10.0, 100.0]), np.array([2.0, 20.0, 200.0]), np.array([3.0, 30.0, 300.0])]
) # an RDD of Vectors
# Compute column summary statistics.
summary = Statistics.colStats(mat)
print(summary.mean()) # a dense vector containing the mean value for each column
print(summary.variance()) # column-wise variance
print(summary.numNonzeros()) # number of nonzeros in each column
# $example off$
sc.stop()

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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// scalastyle:off println
package org.apache.spark.examples.mllib
import org.apache.spark.{SparkConf, SparkContext}
// $example on$
import org.apache.spark.mllib.linalg._
import org.apache.spark.mllib.stat.Statistics
import org.apache.spark.rdd.RDD
// $example off$
object CorrelationsExample {
def main(args: Array[String]): Unit = {
val conf = new SparkConf().setAppName("CorrelationsExample")
val sc = new SparkContext(conf)
// $example on$
val seriesX: RDD[Double] = sc.parallelize(Array(1, 2, 3, 3, 5)) // a series
// must have the same number of partitions and cardinality as seriesX
val seriesY: RDD[Double] = sc.parallelize(Array(11, 22, 33, 33, 555))
// compute the correlation using Pearson's method. Enter "spearman" for Spearman's method. If a
// method is not specified, Pearson's method will be used by default.
val correlation: Double = Statistics.corr(seriesX, seriesY, "pearson")
println(s"Correlation is: $correlation")
val data: RDD[Vector] = sc.parallelize(
Seq(
Vectors.dense(1.0, 10.0, 100.0),
Vectors.dense(2.0, 20.0, 200.0),
Vectors.dense(5.0, 33.0, 366.0))
) // note that each Vector is a row and not a column
// calculate the correlation matrix using Pearson's method. Use "spearman" for Spearman's method
// If a method is not specified, Pearson's method will be used by default.
val correlMatrix: Matrix = Statistics.corr(data, "pearson")
println(correlMatrix.toString)
// $example off$
sc.stop()
}
}
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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// scalastyle:off println
package org.apache.spark.examples.mllib
import org.apache.spark.{SparkConf, SparkContext}
// $example on$
import org.apache.spark.mllib.linalg._
import org.apache.spark.mllib.regression.LabeledPoint
import org.apache.spark.mllib.stat.Statistics
import org.apache.spark.mllib.stat.test.ChiSqTestResult
import org.apache.spark.rdd.RDD
// $example off$
object HypothesisTestingExample {
def main(args: Array[String]) {
val conf = new SparkConf().setAppName("HypothesisTestingExample")
val sc = new SparkContext(conf)
// $example on$
// a vector composed of the frequencies of events
val vec: Vector = Vectors.dense(0.1, 0.15, 0.2, 0.3, 0.25)
// compute the goodness of fit. If a second vector to test against is not supplied
// as a parameter, the test runs against a uniform distribution.
val goodnessOfFitTestResult = Statistics.chiSqTest(vec)
// summary of the test including the p-value, degrees of freedom, test statistic, the method
// used, and the null hypothesis.
println(s"$goodnessOfFitTestResult\n")
// a contingency matrix. Create a dense matrix ((1.0, 2.0), (3.0, 4.0), (5.0, 6.0))
val mat: Matrix = Matrices.dense(3, 2, Array(1.0, 3.0, 5.0, 2.0, 4.0, 6.0))
// conduct Pearson's independence test on the input contingency matrix
val independenceTestResult = Statistics.chiSqTest(mat)
// summary of the test including the p-value, degrees of freedom
println(s"$independenceTestResult\n")
val obs: RDD[LabeledPoint] =
sc.parallelize(
Seq(
LabeledPoint(1.0, Vectors.dense(1.0, 0.0, 3.0)),
LabeledPoint(1.0, Vectors.dense(1.0, 2.0, 0.0)),
LabeledPoint(-1.0, Vectors.dense(-1.0, 0.0, -0.5)
)
)
) // (feature, label) pairs.
// The contingency table is constructed from the raw (feature, label) pairs and used to conduct
// the independence test. Returns an array containing the ChiSquaredTestResult for every feature
// against the label.
val featureTestResults: Array[ChiSqTestResult] = Statistics.chiSqTest(obs)
featureTestResults.zipWithIndex.foreach { case (k, v) =>
println("Column " + (v + 1).toString + ":")
println(k)
} // summary of the test
// $example off$
sc.stop()
}
}
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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// scalastyle:off println
package org.apache.spark.examples.mllib
import org.apache.spark.{SparkConf, SparkContext}
// $example on$
import org.apache.spark.mllib.stat.Statistics
import org.apache.spark.rdd.RDD
// $example off$
object HypothesisTestingKolmogorovSmirnovTestExample {
def main(args: Array[String]): Unit = {
val conf = new SparkConf().setAppName("HypothesisTestingKolmogorovSmirnovTestExample")
val sc = new SparkContext(conf)
// $example on$
val data: RDD[Double] = sc.parallelize(Seq(0.1, 0.15, 0.2, 0.3, 0.25)) // an RDD of sample data
// run a KS test for the sample versus a standard normal distribution
val testResult = Statistics.kolmogorovSmirnovTest(data, "norm", 0, 1)
// summary of the test including the p-value, test statistic, and null hypothesis if our p-value
// indicates significance, we can reject the null hypothesis.
println(testResult)
println()
// perform a KS test using a cumulative distribution function of our making
val myCDF = Map(0.1 -> 0.2, 0.15 -> 0.6, 0.2 -> 0.05, 0.3 -> 0.05, 0.25 -> 0.1)
val testResult2 = Statistics.kolmogorovSmirnovTest(data, myCDF)
println(testResult2)
// $example off$
sc.stop()
}
}
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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// scalastyle:off println
package org.apache.spark.examples.mllib
import org.apache.spark.{SparkConf, SparkContext}
// $example on$
import org.apache.spark.mllib.stat.KernelDensity
import org.apache.spark.rdd.RDD
// $example off$
object KernelDensityEstimationExample {
def main(args: Array[String]): Unit = {
val conf = new SparkConf().setAppName("KernelDensityEstimationExample")
val sc = new SparkContext(conf)
// $example on$
// an RDD of sample data
val data: RDD[Double] = sc.parallelize(Seq(1, 1, 1, 2, 3, 4, 5, 5, 6, 7, 8, 9, 9))
// Construct the density estimator with the sample data and a standard deviation
// for the Gaussian kernels
val kd = new KernelDensity()
.setSample(data)
.setBandwidth(3.0)
// Find density estimates for the given values
val densities = kd.estimate(Array(-1.0, 2.0, 5.0))
// $example off$
densities.foreach(println)
sc.stop()
}
}
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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// scalastyle:off println
package org.apache.spark.examples.mllib
import org.apache.spark.{SparkConf, SparkContext}
object StratifiedSamplingExample {
def main(args: Array[String]): Unit = {
val conf = new SparkConf().setAppName("StratifiedSamplingExample")
val sc = new SparkContext(conf)
// $example on$
// an RDD[(K, V)] of any key value pairs
val data = sc.parallelize(
Seq((1, 'a'), (1, 'b'), (2, 'c'), (2, 'd'), (2, 'e'), (3, 'f')))
// specify the exact fraction desired from each key
val fractions = Map(1 -> 0.1, 2 -> 0.6, 3 -> 0.3)
// Get an approximate sample from each stratum
val approxSample = data.sampleByKey(withReplacement = false, fractions = fractions)
// Get an exact sample from each stratum
val exactSample = data.sampleByKeyExact(withReplacement = false, fractions = fractions)
// $example off$
println("approxSample size is " + approxSample.collect().size.toString)
approxSample.collect().foreach(println)
println("exactSample its size is " + exactSample.collect().size.toString)
exactSample.collect().foreach(println)
sc.stop()
}
}
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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// scalastyle:off println
package org.apache.spark.examples.mllib
import org.apache.spark.{SparkConf, SparkContext}
// $example on$
import org.apache.spark.mllib.linalg.Vectors
import org.apache.spark.mllib.stat.{MultivariateStatisticalSummary, Statistics}
// $example off$
object SummaryStatisticsExample {
def main(args: Array[String]): Unit = {
val conf = new SparkConf().setAppName("SummaryStatisticsExample")
val sc = new SparkContext(conf)
// $example on$
val observations = sc.parallelize(
Seq(
Vectors.dense(1.0, 10.0, 100.0),
Vectors.dense(2.0, 20.0, 200.0),
Vectors.dense(3.0, 30.0, 300.0)
)
)
// Compute column summary statistics.
val summary: MultivariateStatisticalSummary = Statistics.colStats(observations)
println(summary.mean) // a dense vector containing the mean value for each column
println(summary.variance) // column-wise variance
println(summary.numNonzeros) // number of nonzeros in each column
// $example off$
sc.stop()
}
}
// scalastyle:on println